The Indian Ocean Observing System (IndOOS) has provided “unprecedented measurements of weather, ocean and climate phenomena,” according to a case study of the system published by the Commonwealth Blue Charter. IndOOS is a multigovernmental, multi-institutional ocean monitoring project undertaken by the 22 countries that surround the Indian Ocean.
“If you want to forecast weather for the next few days, observing the atmosphere is more than enough. But if you want long-term forecasts, the memory is available only in the oceans, so we have to depend on oceans,” said M. Ravichandran, secretary of India’s Ministry of Earth Sciences.
Around 2000, many countries realized that the Indian Ocean helps drive an array of global phenomena, from extreme weather in Australia to increased precipitation in East Africa. Recognizing the need for better monitoring, the Indian Ocean Region Panel (part of the World Climate Research Programme) and the Global Ocean Observing System (GOOS) set up IndOOS. “This panel laid out what needs to be observed, where it needs to be observed, and the parameters for such observations,” Ravichandran added. He himself has worked with the Indian Ocean Region Panel for more than a decade, first as a representative from India and later as a cochair.
With the help of IndOOS, Ravichandran explained, “India has been able to transform from a statistical model of forecasting based on correlation to a dynamic one that tracks factors like heat and mass in the atmosphere and the ocean.”
For India, the biggest gains offered by IndOOS are better monsoon prediction and understanding how the Indian Ocean is warming. Observing the ocean is key to predicting and mitigating the effects of major climate hazards like cyclones and sea level rise.
The value of IndOOS extends far beyond India, however. “Variability in the tropical and subtropical Indian Ocean influences the weather affecting the east coast of Africa,” said Juliet Hermes, manager and principal oceanographer at the South African Environmental Observation Network and current cochair of the Indian Ocean Region Panel.
Elaborating on the importance of an observation system for Indian Ocean countries as a whole, Roxy Mathew Koll, another cochair of the Indian Ocean Region Panel, said that people living on the rim of the ocean, especially in low-lying areas, “are highly susceptible to sea level rise, intense cyclones, and flooding because of heavy rainfall.”
To have sufficient lead time to respond to disasters like cyclones, “we need accurate predictions based on surface and subsurface ocean monitoring and also data sharing across countries, and this is what IndOOS provides,” Koll added.
In response to why the Commonwealth Secretariat picked IndOOS as a case study worth highlighting, Nicholas Hardman-Mountford, the organization’s head of Oceans and Natural Resources, said the Indian Ocean region is “overwhelmingly bordered by countries of the Global South as well as being absolutely crucial for the global ocean economy and livelihoods of billions of people.” He added that IndOOS made “huge strides” in helping scientists better understand complex ocean processes like the Indian Ocean Dipole, the heat fluxes that drive the monsoon, and the ultralow-oxygen waters spread throughout the Arabian Sea and Bay of Bengal.
Scope for IndOOS Improvement
The Blue Charter case study is based on a November 2020 study of IndOOS that sought to highlight the need for enhancing the system so that it could better meet societal challenges and provide more reliable forecasts. Koll is one of the authors of the 2020 study.
Currently, IndOOS has a big monitoring gap with respect to sharing data related to participating countries’ exclusive economic zones (EEZs). “Because governments do not share [these] data, it affects forecasts, because global weather models cannot take this area into account,” Koll said. The Blue Charter study specifically notes the need for “political will” to allow observational access to EEZs.
Another monitoring gap is in the western Indian Ocean around Somalia—a gap associated with piracy in the region. “Research vessels have been advised to not venture into this area and not to install monitoring instruments, but this region of the western Indian Ocean is important for monitoring monsoon winds,” Koll said.
More broadly, there is “an urgent need to address the sustainability of IndOOS and its expansion, in particular, to ensure increased observations in the tropical and subtropical Indian Ocean,” Hermes said. For instance, she explained, consider how South Africa could deploy the Agulhas System Climate Array for only a short period between 2016 and 2018 because of funding constraints. The array is essential for understanding the Agulhas Current’s volume, heat, and salt transport, which are essential in regional weather patterns and also key components for global thermohaline circulation and climate in regions as far afield as northern Europe.
Scientists also hope to expand local funding for IndOOS. Since its inception, most of the project’s funding has come from outside the region: the United States, China, South Korea, and Europe. Australia and India (and, increasingly, Indonesia and South Africa) do play a strong role, but engagement is weighed toward those outside the immediate area. “These investments are incredibly important and welcome, but the side effect is that the majority of scientists working on the Indian Ocean are from outside the region and most Indian Ocean rim countries are not well engaged with the observing system,” Hardman-Mountford said.
Finally, scientists support increasing IndOOS observation beyond its current 2,000-meter depth. “We need full-depth ocean measurements to understand ocean warming,” Ravichandran said. Even greater enlargement may include expanding the network to monitor not just salinity and temperature but also the ecosystem itself in terms of ocean acidity, chlorophyll and oxygen content, and impacts on fisheries.
—Rishika Pardikar (@rishpardikar), Science Writer